At last, DC collects Jack Kirby’s run of adventure epics from SHOWCASE #6, 7, 11 and 12 and CHALLENGERS OF THE UNKNOWN #1-8 in a single paperback volume! These are the tales that introduced Ace Morgan, Red Ryan, Rocky Davis and Professor Haley—four men living on borrowed time, determined to face—and overcome—adversity in the form of monsters, aliens and would-be world conquerors!